ref: 673e3de9a2f59dbac9a845b2f28363b2bb9f0041
dir: /kern/allocb.c/
#include "u.h" #include "lib.h" #include "dat.h" #include "fns.h" #include "error.h" enum { Hdrspc = 64, /* leave room for high-level headers */ Bdead = 0x51494F42, /* "QIOB" */ }; struct { Lock lk; ulong bytes; } ialloc; static Block* _allocb(int size) { Block *b; uintptr addr; if((b = mallocz(sizeof(Block)+size+Hdrspc, 0)) == nil) return nil; b->next = nil; b->list = nil; b->free = 0; b->flag = 0; /* align start of data portion by rounding up */ addr = (uintptr)b; addr = ROUND(addr + sizeof(Block), BLOCKALIGN); b->base = (uchar*)addr; /* align end of data portion by rounding down */ b->lim = ((uchar*)b) + sizeof(Block)+size+Hdrspc; addr = (uintptr)(b->lim); addr = addr & ~(BLOCKALIGN-1); b->lim = (uchar*)addr; /* leave sluff at beginning for added headers */ b->rp = b->lim - ROUND(size, BLOCKALIGN); if(b->rp < b->base) panic("_allocb"); b->wp = b->rp; return b; } Block* allocb(int size) { Block *b; /* * Check in a process and wait until successful. * Can still error out of here, though. */ if(up == nil) panic("allocb without up: %p\n", getcallerpc(&size)); if((b = _allocb(size)) == nil){ panic("allocb: no memory for %d bytes\n", size); } setmalloctag(b, getcallerpc(&size)); return b; } Block* iallocb(int size) { Block *b; static int m1, m2; if(ialloc.bytes > conf.ialloc){ if((m1++%10000)==0) print("iallocb: limited %lud/%lud\n", ialloc.bytes, conf.ialloc); return 0; } if((b = _allocb(size)) == nil){ if((m2++%10000)==0) print("iallocb: no memory %lud/%lud\n", ialloc.bytes, conf.ialloc); return nil; } setmalloctag(b, getcallerpc(&size)); b->flag = BINTR; ilock(&ialloc.lk); ialloc.bytes += b->lim - b->base; iunlock(&ialloc.lk); return b; } void freeb(Block *b) { void *dead = (void*)Bdead; if(b == nil) return; /* * drivers which perform non cache coherent DMA manage their own buffer * pool of uncached buffers and provide their own free routine. */ if(b->free) { b->free(b); return; } if(b->flag & BINTR) { ilock(&ialloc.lk); ialloc.bytes -= b->lim - b->base; iunlock(&ialloc.lk); } /* poison the block in case someone is still holding onto it */ b->next = dead; b->rp = dead; b->wp = dead; b->lim = dead; b->base = dead; free(b); } void checkb(Block *b, char *msg) { void *dead = (void*)Bdead; if(b == dead) panic("checkb b %s %lux", msg, b); if(b->base == dead || b->lim == dead || b->next == dead || b->rp == dead || b->wp == dead){ print("checkb: base 0x%8.8luX lim 0x%8.8luX next 0x%8.8luX\n", b->base, b->lim, b->next); print("checkb: rp 0x%8.8luX wp 0x%8.8luX\n", b->rp, b->wp); panic("checkb dead: %s\n", msg); } if(b->base > b->lim) panic("checkb 0 %s %lux %lux", msg, b->base, b->lim); if(b->rp < b->base) panic("checkb 1 %s %lux %lux", msg, b->base, b->rp); if(b->wp < b->base) panic("checkb 2 %s %lux %lux", msg, b->base, b->wp); if(b->rp > b->lim) panic("checkb 3 %s %lux %lux", msg, b->rp, b->lim); if(b->wp > b->lim) panic("checkb 4 %s %lux %lux", msg, b->wp, b->lim); } void iallocsummary(void) { print("ialloc %lud/%lud\n", ialloc.bytes, conf.ialloc); }